Drier-mixing apparatus

ABSTRACT

A drier-mixing apparatus in which a rotatably driven drum provided with opposed inlet and outlet ends has a plurality of vanes mounted therein. An inlet chute is mounted at the inlet end of the drum for introducing materials into said drum and the outlet end of the drum is provided with a discharge opening. Burners are mounted at the drum inlet and outlet ends to discharge flames into said drum. Air collecting ducts are also mounted at the drum inlet and outlet ends and are connected to dust collectors for removing the gases and the solid particles suspended therein from the drum.

United States Patent 1191 McConnaughay I Oct. 8, 1974 1 DRIER-MIXINGAPPARATUS Prima Examiner-Robert W. Jenkins [76] Inventor: Kenneth E.McConnau ha R0. 1

I BOX 1457, Lafayette, i Attorney, Agent, or Fzrm-Trask, Jenkms & Hanley22 Fl (1: .12 1973 21 A l N 91; [57] ABSTRACT 1 PP 2 A A drier-mixingapparatus in which a rotatably driven drum provided with opposed inletand outlet ends has [52] US. Cl. 259/158, 34/108 a plurality of vanesmounted therein. An inlet Chute is [51] Int. Cl. 1328c 1/22 mou t d tthe inlet end of the drum for introducing Fleld 0f Search 157, materialsinto said drum and the outlet end of the 1 R, 17 177 3, drum is providedwith a discharge opening. Burners 34/108, 130, 135, 13 137 are mountedat the drum inlet and outlet ends to dis- 1 charge flames into saiddrum. Air collecting ducts are References Cited also mounted at the druminlet and outlet ends and UNITED STATES PATENTS are connected to dustcollectors for Iremoving the 1,240,481 9/1917 Popkess 259/158 gases andthe SOIid'PaYtiCIeS Suspended therein from 2,188,798 1/1940 Smith259/155 the drum- 1 2,305,938 12/1942 1 Turnbull 259/158 2,421,3455/1947 McConnaughay 159/152 6 Clams 3 D'awmg Flgures 7o 5 59 59 1s 77 4547 2 e m 5 45 4 2O 2 5e 1 i 24 i i. i Z 27 35 i 57 26 7 PATENIEDBET 81w3,840,215 V SHEEI l 0? 4 m H. I Q

DRIER-MIXING APPARATUS BACKGROUND OF THE INVENTION one end of the drum,andhave employed an exhaust fan at the same or opposite end of the drum.In such driers, the burner cannot normally furnish heat for the entirelength of the drier, which results in a nonuniform heating of thematerials passing through the drum. In addition, the exhaust fan mustproduce an extherethrough, have a lower operating cost than conventionaldriers, and produce less pollution.

SUMMARY OF THE INVENTION In accordance with one form of the invention, adrum is rotatably mounted on a supporting frame and connected to adriver unit. The ends of the drum are closed by apair of end plates. Aninlet chute is mounted on one of said plates in open communication withan inlet opening in said plate for introducing the aggregate materialsto'be processed into the drum. The other end plate is provided with-adischarge opening for removing the processed materials from the drum.

A pair of burners are mounted on the frame at the opposed ends of thedrum. Each of the end plates has an opening formed therein in alignmentwith its adjacent burner whereby'said burners inject flames into thedrum from both the inlet and outlet ends thereof.

A plurality of vanes are mounted in the drum for lifting and droppingthe materials passing therethrough. The vanes are disposed in anoverlapping relationship adjacentthe center of the drum to assure adense curtain of said material dropping across the center of the drum.Desirably, a plurality of pusher blades disposed at an angle to the axisof the drum are mounted in the drum adjacent its inlet end for quicklyadvancing the material toward the center of the drum after it hasentered through the inlet opening.

A pair of ducts are mounted on the end plates and are disposed in opencommunication with the interior of the drum by openings formed in saidplates. The ducts are each connected to a knock-out box for collectingdust and other solid particles. Each of the knock-out boxes has anoutlet conduit which is connected to an exhaust fan, which fan pulls thegaseous materials, and the solid particles suspended therein, out of thedrum and through the ducts and into knock-out boxes.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustratethe invention.

FIG. 1; 7 FIG. 3 is an axial section taken on line 3-3 of FIG.

FIG. 4'is an end elevation "of the outlet end of the drum shown in FIG.1;

FIG. 5 is an end elevation of theinlet end of the drum shown in FIG. 1;I

FIG. 6-is an enlarged vertical section taken on the line 6-6 of FIG. 2;

FIG. 7 is an axial section similar to FIG. 3 but showing a modified formof the invention, and

FIG. 8 is a side elevation of the drum disc shown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED I EMBODIMENT The instant inventionis particularly well adapted for use in the paving industry for dryingaggregates and removing the dust particles and fines therefrom. Inaddition, it can be employed to mix such aggregates with variousbituminous binders to produce pavingcompositions while maintaining thenormally attendant atmospheric pollution to a minimum.

As shown in FIG. 1, the apparatus comprises a drum 10 carried on asupporting frame 12 with its axisinclined to the horizontal.Conveniently, as is illustrated in FIG. 1, the frame 12 can be the bedof a truck trailer supported in a non-horizontal orientation by cribbing13. The drum is rotatably supported on the frame by a plurality of rings14 mounted on the outer face of the drum and carried in rollers 15mounted on frame 12. The drum is rotatably driven by a motor 16 mountedon frame 12 and operatively connected to a chain 18 received on asprocket 20 extending around the drum 10. I

The drum inlet end 22 is disposed at its upper end and its outlet end 24is-disposed at its lower end. As best shown inFIG. 3, the inlet end 22is closed by an end plate .25 mounted on frame 12. Plate 25 has anopening 26 through which aggregate is introduced into the drum through achute 27 mounted on plate 25. Conveniently, the aggregate may be fed tochute 27 through a conventional belt conveyor- (not shown) leading froman aggregate stock pile. The outlet end 24. of the drum is enclosed byan end plate 30 fixedly mounted on frame 12. As shown in FIG. 4, adischarge opening 31 is provided in plate 30 through which the aggregateis discharged'from drum 10.

In order to permit the aggregate to be mixed with a binder and form apaving composition therewith, a pipe 35 connected to a source 36 of saidbinder projects into the drum through a sleeved opening 37 in plate 25.A nozzle 38 is mounted on the inner. end of the pipe to provide thedesired spray pattern within the drum. It is frequently desirable to mixwater or water solutions of adhesion or cohesion promoters with thebinder. To

this end, a second pipe 39 connected to a source 40 of said water orwater solutions is connected to the'pipe 35 upstream of the opening 37.The pipes 35 and 39 are connected by flexible hoses 41 to conventionalproportioners 42 connected to the supply sources 36 and 40. The pipe 35is slidably carried in the end plate 25 to thus permit the nozzle 38 tobe moved into the desired longitudinal position of adjustment within thedrum.

It is to be understood, of course, that if the apparatus is to be usedonly for drying the aggregate, the pipes 35 and 39 can be completelywithdrawn from the drum 10 Two sets of axially extending,circumferentially spaced, vanes 45 are mounted on the inner face of thedrum and project inwardly therefrom for lifting and droppingtheaggregate within said drum as it is rotated.

posite sides of the center of the drum and a third set of axiallyextending, circumferentially spaced vanes 46 are mounted within the drumadjacent the center thereof. The vanes 46 are radially offset withrespect to the vanes 45 and have their opposed ends interposed betweenadjacent pairs of the vanes 45 to thus dispose the vanes 45 and 46 in anoverlapping relationship. This orientation of the vanes 45-and 46 at thecenter of the drum creates a more dense curtain of aggregate lifting andfalling within the drum adjacent the center thereof.

A set of pusher vanes 47 are mounted within the drum adjacent the inletend 22. As shown, the vanes 47 are disposed at an angle to the drum axisfor thus initiating the flow of the aggregate downwardly along thelength of the drum after it has been introduced through the inletopening 26 of plate 25.

A pair of burners 48 and 49 are mounted on frame 12 adjacent the inletand outlet ends of drum 10. The burners are identical in theirconstruction, and each is provided with a nozzle 50 and a blower 51. Thenozzle 50 on burner 48 is disposed in alignment with an opening 52 inplate 25, and in a like manner, nozzle 50 on burner 49 is disposed inalignment withan opening 53 in plate 30. The blowers 51 on burners 48and 49 furnish all of the necessary air of combustion. The pres sure'onthe blowers and the noz'zlescan be adjusted so that the flame from eachof the burners 48 and 49 will be of the desired shape and will extendinto the drum to the center thereof. This causes the flames from'the twoburners to meet adjacent the center of the drum and to turn outwardlyand backwardly toward each end of the drum. With the vanes 45 and 46increasing the density of the aggregate curtain dropping across thecenter of the drum, said flames will tend to further be turned back fromthe center of the drum toward their respective burners.

Air ducts 54 and 55 extend across the upper ends of, and are connectedto, the end plates 25 and 30, respectively. As shown in FIG. 3, duct 54is in open communication with the upper end of the drum through anopening 56 in plate 25.'In a like manner, duct 55 is in opencommunication with the upper end of the drum at its outlet end throughan opening 57 formed in plate 30. Each of ducts 54 and 55 is provided atone of its ends with a damper 58. The opposite end of each of said ductsis connected to a knock-out box 59 supported on a plurality of legs 61.v

The knock-out boxes 59 are identical in their construction. As shown inFIG. 6, each of the boxes 59 comprises a plurality of side walls 60 toone of which the duct 54 or 55 is connected. The top of the box isclosed by a top wall 62, and a pair of the side walls 60 slope inwardlyadjacent their lower ends and are interconnected at their lower ends bya floor 64. A drawer 66 is slidably mounted in the lower end of the box59 for removing any dust or solid particles collected therein. A baffleplate 68 extends across the box 59 to provide a circuitous gas flowtherethrough. By interrupting the air flow through the boxes, the plates68 cause the dust and solid particles to drop out of the gases into thedrawers 66.

The gases are discharged from each of the boxes 59 through a dischargeconduit 70 connected to the top As shown in FIG. 3, the two sets ofvanes 45 are on opwall 62. The discharge conduits 70, at their ends remote from boxes 59, are connected to the cross arm of a T-shaped conduit73. The leg 74 of the conduit 73 is connected to an exhaust fan 76provided with a discharge stack 77. The fan 76 is driven by any desiredtype of drive motor 78. Thus, the exhaust fan 76 pulls the gaseousmaterials and any solid or dust particles suspended therein from thedrum 10 through ducts 54 and 55 into the knock-out boxes 59 where thedust or solid particles are removed from said gaseous materials. Thegaseous materials, free from the dust and solid particles, are pulledfrom the boxes 59 through the conduits and 73 for discharge through theexhaust stack 77.

7 As will be apparent, the aggregate'to be dried or coated with a binderwill enter the drum through the chute 27 and will be constantly liftedand dropped as it moves through said drum through the action of thevanes 45-47. During its movement through the drum, said aggregate or theaggregate binder mixture will be subjected to the heating action of theflames discharged from the burners 48 and 49, which flames extend forsubstantially the entire length of the drum. The dust and other lightweight particulate matter in the aggregate is removed therefrom throughthe ducts 54 and 55 and is deposited in the knock-out boxes 59 so thatthe gaseous discharge from the stack 77 will be substantially pollutionfree.

The embodiment of the invention illustrated in FIG. 7 differs fromembodiment in FIGS. 1 -6 solely in the means for creating a more densecurtain of the aggregate falling across the center of the drum. In theembodiment shown in FIG. 7, the vanes 46 are eliminated from the drum10'. As shown in FIG. 7, interposed between the adjacent ends of sets ofvanes 45' is a disk 80 extending across the drum. As shown, said diskhas a plurality of large openings 82 extending therethrough adjacent itscircumference. Thus, theaggregate moving along drum 10 will strike disk80 and will have its movement impeded thereby to create a dense curtainof aggregate adjacent the center of the drum. The openings 82, however,permit said aggregate to pass through the disk to the discharge end ofthe drum. F urther, said disk tends to reverse the flow of the flamesfrom burners 49' and the burner at the opposite drum end (not shown) tocause said flames to be directed backwardly toward the drum end plates25 and 30'.

As will be appreciated, except for the disk 80, the apparatusillustrated in FIG. 7 is in all respects the same as the apparatusillustrated in FIGS. 1-6.

I claim:

1. A drier-mixing apparatus, comprising a drum rotatably mountedon aframe having an inlet at one of its ends and an outlet at its oppositeend, means for rotating said drum, a plurality of vanes mounted in saiddrum for mixing the materials passing through said drum, air collectingmeans at the top of the drum at the inlet and outlet ends thereof, aburner at each of said inlet and outlet ends for blowing flames intosaid drum from the opposite ends thereof, and exhaust means connected tosaid air collecting means for pulling air and dust particles throughsaid air collecting means from said drum.

2. A drier-mixing apparatus as set forth in claim 1 in which said vanescomprise first and second sets of circumferentially spaced axiallyextending vanes disposed on opposite sides of the center of the drum,and a third set of circumferentially spaced axially extending vanes atthe center of said drum, said third set of vanes being circumferentiallyoffset with respect to said first and second sets of vanes with the endsof the vanes in said third set extending between the ends of adjacentpairs of vanes in said first and second sets.

3. A drier-mixing apparatus as set forth in claim 2 with the additionthat a plurality of pusher vanes are mounted in said drum between saidfirst set of vanes and the drum inlet end, said pusher blades beingangularly offset with respect to the axis of said drum.

4. A drier-mixing apparatus as set forth in claim 1 with the additionthat an apertured disk is mounted in said drum and extends thereacrossadjacent the center of said drum.

5. A drier-mixing apparatus, comprising a drum rotatably mounted on aframe, a pair of end plates mounted on said frame at the opposed ends ofsaid for mixing the materials passing therethrough, an inlet chutemounted on one of said end plates, a discharge opening formed in theother of said end plates, a pair of air ducts mounted on said end platesin open communication with said drum, an exhaust fan interconnected tosaid air ducts for evacuating gaseous materials from said drum, meansinterconnected to said ducts and exhaust fan for collecting solidparticles suspended in said gaseous materials, a pair of burners mountedon said frame at the opposed ends of said drum, each of said burnersbeing provided with a nozzle disposed in alignment with an opening inone of the end plates for blowing the flame from the burners into thedrum, and a pipe carried in one of said end plates and connected to asource of binder material for injecting a binder into said drum.

6. A drier-mixing apparatus as set forth in claim 5 with the additionthat each of said air ducts has a damper mounted thereon.

1. A drier-mixing apparatus, comprising a drum rotatably mounted on aframe having an inlet at one of its ends and an outlet at its oppositeend, means for rotating said drum, a plurality of vanes mounted in saiddrum for mixing the materials passing through said drum, air collectingmeans at the top of the drum at the inlet and outlet ends thereof, aburner at each of said inlet and outlet ends for blowing flames intosaid drum from the opposite ends thereof, and exhaust means connected tosaid air collecting means for pulling air and dust particles throughsaid air collecting means from said drum.
 2. A drier-mixing apparatus asset forth in claim 1 in which said vanes comprise first and second setsof circumferentially spaced axially extending vanes disposed on oppositesides of the center of the drum, and a third set of circumferentiallyspaced axially extending vanes at the center of said drum, said thirdset of vanes being circumferentially offset with respect to said firstand second sets of vanes with the ends of the vanes in said third setextending between the ends of adjacent pairs of vanes in said first andsecond sets.
 3. A drier-mixing apparatus as set forth in claim 2 withthe addition that a plurality of pusher vanes are mounted in said drumbetween said first set of vanes and the drum inlet end, said pusherblades being angularly offset with respect to the axis of said drum. 4.A drier-mixing apparatus as set forth in claim 1 with the addition thatan apertured disk is mounted in said drum and extends thereacrossadjacent the center of said drum.
 5. A drier-mixing apparatus,comprising a drum rotatably mounted on a frame, a pair of end platesmounted on said frame at the opposed ends of said drum for closing saiddrum ends, means for rotating said drum, a plurality of vanes mounted insaid drum for mixing the materials passing therethrough, an inlet chutemounted on one of said end plates, a discharge opening formed in theother of said end plates, a pair of air ducts mounted on said end platesin open communication with said drum, an exhaust fan interconnected tosaid air ducts for evacuating gaseous materials from said drum, meansinterconnected to said ducts and exhaust fan for collecting solidparticles suspended in said gaseous materials, a pair of burners mountedon said frame at the opposed ends of said drum, each of said burnersbeing provided with a nozzle disposed in alignment with an opening inone of the end plates for blowing the flame from the burners into thedrum, and a pipe carried in one of said end plates and connected to asource of binder material for injecting a binder into said drum.
 6. Adrier-mixing apparatus as set forth in claim 5 with the addition thateach of said air ducts has a damper mounted thereon.